Dinosaurs’ Legend

From dinosaur fossils found throughout the world, scientists have gained evidence about when dinosaurs lived, what they ate, and how large they grew. Dinosaurs lived during the Mesozoic era, from 225 to 65 million years ago. The Mesozoic era is divided into three periods: Triassic, Jurassic, and Cretaceous.

TRIASSIC PERIOD, from 225 to 195 million years ago
First dinosaurs appeared during the Triassic period. Most early dinosaurs were small, rarely longer than 15 feet.
Early meat-eating dinosaurs were called Theropods.
Earliest-known dinosaurs were meat-eaters, found in Argentina: Eoraptor (the most primitive dinosaur, only about 40 inches long) and Herrerasaurus.
Early plant-eating dinosaurs were called Prosauropods. Plateosaurus and Anchisaurus were two early plant-eating dinosaurs.

JURASSIC PERIOD, from 195 to 135 million years ago
Dinosaurs that lived during the Jurassic period were gigantic.
Jurassic dinosaurs included the Sauropods, giant long-necked plant-eaters, the largest land animals ever. Apatosaurus and Brachiosaurus (70-80feet) and Diplodocus (over 80 feet) were Sauropods.
Stegosaurus (30 feet), a large plant-eater, had sharp, bony plates along its back.
Allosaurus and Megalosaurus, two giant meat-eaters, fed on large plant-eating dinosaurs like the Apatosaurus and Stegosaurus. Megalosaurus grew to 30 feet in length; Allosaurus, 30-36 feet.

CRETACEOUS PERIOD, from 135 to 65 million years ago
New dinosaurs appeared during the Cretaceous period, but by the end of the Cretaceous period, all dinosaurs had died out.
New plant-eaters: Triceratops and other horned dinosaurs, Anatosaurus and other duckbilled dinosaurs, Ankylosaurus and other armored dinosaurs.
New meat-eater: Tyrannosaurus Rex, the largest and one of the fiercest meat-eaters, growing to 20 feet high and 40 feet long.

DID YOU KNOW?
Tyrannosaurus Rex had teeth that were 7 inches long!
Sauropods had teeth that were not good for chewing, so they ate
stones, which ground up the food in their stomachs.
The Stegosaurus had the smallest brain of any dinosaur. Its
brain weighed only 2.5 ounces.
Scientists studying dinosaur bones believe that birds are probably
descended from small dinosaurs.

Although we do not know for sure why dinosaurs became extinct, one theory is that an asteroid from space hit the Earth 65 million years ago and blocked out the sunlight. This possibly caused drastic climate changes that made the dinosaurs starve to death.

Source: World Almanac for Kids